Home refrigerator in catamaran?

[Palarran]

I have to investigate that further. I have an autotransformer which can split the voltage for my normal 120v plug outlets. I'm just not sure how 230 split phase going into the Victron is going to work and how it's going to come out.

As for the refrigerator power. I bought a seperate inverter for it but at 2000w. I just can't see these units drawing less than 5 amps when running at 120v or 600 watts. I don't want it always maxing out the inverter and compared the standby watts of the 1000 vs 2000. I think it was like 5 watts difference. That didn't seem like enough to bother going with the smaller unit and now I have a backup.

[nebster]

Originally Posted by Palarran

I have to investigate that further. I have an autotransformer which can split the voltage for my normal 120v plug outlets. I'm just not sure how 230 split phase going into the Victron is going to work and how it's going to come out.

So, in North American with split phase 240V shore supply, you can run the 240V into a 240V Victron and then on the output side put the autotransformer to create your two 120V circuits, or at least that's how I do it. Generator also makes 240V.

In those cases, we just discard the neutral line on the input wiring side.

The A-T needs to be wired correctly so that it can re-create the neutral bond when the inverter is operating without a shore supply. This takes a little doing, but it's easy in the end.

[Palarran]

I think I'll start a different thread about wiring up a 230v inverter/charger for split phase input.

One question though is about the separate inverter. Here is the data sheet for Xantrex. I read it that the efficiency while inverting is 90% for both the 1000 and 2000 watt units and that the no load watt draw is .6a and .8a respectively. Is that at 120v or 12v? It still seems like a low watt draw difference to not get the 2000 watt unit.

https://www.defender.com/pdf/204823-25_Xantrex.pdf

[44'cruisingcat]

The draw when idle would be on the 12v side, as by definition, there's no draw on the 240 volt side at idle.

[myocean]

The RB29HER2CSA has efficiency rating A++ only. Why not go for a similar A+++ model?
How much energy do you have available?

I would as well consider that storing fruits in the fridge is generally not a good idea for cruising - so what is your wife going to do with all the space?
You may want to look into tipps for fresh produce storage.

[mako]

I have researched the Samsung A+++ fridges with digital inverter motors. They are excellent for boats, if you can fit a domestic sized unit.

The model I was looking at was around 335 liters (roughly). I got in touch with Samsung engineering depart. According to them, the unit draws a maximum of 800 watts while operating, with the heater (defrost) coils using 150 watts (+3 watts for a fan). Since they are digital inverter they ramp up to speed, so there is no locked rotor draw.

Daily consumption was consistent with the labels, so about 500 watts per day, and they would run comfortably with a PSW inverter of about 1000 watts.

I found the difference in energy usage rather considerable between the A++ and the A+++ units.

[Palarran]

Originally Posted by makobuilders

I have researched the Samsung A+++ fridges with digital inverter motors. They are excellent for boats, if you can fit a domestic sized unit.

The model I was looking at was around 335 liters (roughly). I got in touch with Samsung engineering depart. According to them, the unit draws a maximum of 800 watts while operating, with the heater (defrost) coils using 150 watts (+3 watts for a fan). Since they are digital inverter they ramp up to speed, so there is no locked rotor draw.

Daily consumption was consistent with the labels, so about 500 watts per day, and they would run comfortably with a PSW inverter of about 1000 watts.

I found the difference in energy usage rather considerable between the A++ and the A+++ units.

So if I understand what you are saying, the unit draws 800 watts when running and only consumes 500 watts per day. Does that mean that the refrigerator only runs 35 minutes per day? How does it cool new warm food put in it and recool all the air that drops out when you open the door?

[44'cruisingcat]

Originally Posted by Palarran

So if I understand what you are saying, the unit draws 800 watts when running and only consumes 500 watts per day. Does that mean that the refrigerator only runs 35 minutes per day? How does it cool new warm food put in it and recool all the air that drops out when you open the door?

Maximum 800 Watts doesn't mean drawing 800 Watts all the time its running. (Obviously.) Our fridge can draw up to 600 Watts for a moment on compressor startup, but it only draws 60 Watts when running. Fridges with frost free systems could draw even more at times because they have heating elements. But these systems don't operate constantly.

[CatNewBee]

the issue with the fridge is the size, there is only 180cm space on the height available to fit it in the corner, also only a 65 x 60cm area. A side by side would not work, and the Admirals wants freezer space, so it should be a unit with two doors. The A+++ are usually taller, I did not found one hat would fit in there.

Regarding the Inverter, I have a Victron Quattro 5000 and it has some energy saving features, but they can confuse modern power supplies, that draw very little power, like the panels on fridges, ovens, induction hobs with touch interfaces, so you cannot use them. The inverter alone draws around 3A in idle, so 3.5A with connected appliances with LED, displays, touch UI, that easily adds up to 70..80Ah per day - more than the fridge would draw. A smaller inverter dedicated only to the fridge would draw probably 1/10th, that would be OK, the big one is on only when the other appliances are in use.

.
Assuming 252kWh annual energy translates to 690Wh per day or 57Ah daily consumption.


The 12V 2 fridges/ 1 freezer currently installed draw between 15 to 20A constantly, very inefficient in respect to fridge space, and space used in the galley.

[mako]

Originally Posted by 44'cruisingcat

Maximum 800 Watts doesn't mean drawing 800 Watts all the time its running. (Obviously.) Our fridge can draw up to 600 Watts for a moment on compressor startup, but it only draws 60 Watts when running. Fridges with frost free systems could draw even more at times because they have heating elements. But these systems don't operate constantly.

44'CC is correct. The beauty lies in the digital inverter technology. It is basically a variable speed compressor that ramps up to speed when starting. So not only can it run at 25% if that is all that is required, it does not draw 6X its rated power "locked rotor." Those are some of the reasons why these domestic units run more efficiently than the magical 12VDC Danfoss units that sailboaters like to brag about. The only fridges I've found which are more efficient are the Sunfrosts, but they cost over $2000.

CatNewBee, there are so many of these super-efficient units for sale from most major brands, in different sizes. Just keep shopping around. Even an A++ is still an excellent choice. But if you are running a giant 5kW inverter then definitely buy a tiny, dedicated PSW inverter to power the fridge. Take some measurements first though of its actual running load, perhaps at your house, for a week or two. You might wind up with just a 500 or 600 watt unit needed.

[CatNewBee]

We are still undecided and shopping around, There are other alternatives like a A+++ Freezer only, that is even more efficient with only 150kWh / year in about the same size.

I will also check out the idle current consumption of the Mastervolt MassSine 2kVA inverter I have still installed (it came with the boat), if it is not too bad, this could be an option to rung the fridge / freezer and have some of the outlets for smaller loads always powered.

This will happen during the year while cruising the Med I guess. At the moment it is only planning and searching for a good solution.

[Simi 60]

Originally Posted by makobuilders

But if you are running a giant 5kW inverter then definitely buy a tiny, dedicated PSW inverter to power the fridge. Take some measurements first though of its actual running load, perhaps at your house, for a week or two. You might wind up with just a 500 or 600 watt unit needed.

We run a 5kw inverter and household refrigeration but no dedicated PSW.
Everything is fine, the world did not end.

[Simi 60]

Originally Posted by CatNewBee

.

Regarding the Inverter, I have a Victron Quattro 5000 and it has some energy saving features, but they can confuse modern power supplies, that draw very little power, like the panels on fridges, ovens, induction hobs with touch interfaces, so you cannot use them. .

We have not found that to be the case.
Admittedly it is just the fridge with an electronic front panel.

[CatNewBee]

Originally Posted by Simi 60

We have not found that to be the case.

Well, I have observed it by measuring the 12V side. You can also see it in the software when connecting the MkII usb interface. The pulsing feature poweres the appliances displays and user interfaces on and stays on in standard setting, you can mess with the thresholds for the detection of loads to force the inverter to sleep again, but then they turn on and off all the time.

The second setting is the modified wave form thing, that causes 30% drop of the energy, but some gadgets really want a sine wave to operate properly and can get damaged otherwise. Also saving is marginal, around 0.5A less only (2.5...2.75A), so not worth the hussle.

[Simi 60]

Originally Posted by CatNewBee

Well, I have observed it by measuring the 12V side. You can also see it in the software when connecting the MkII usb interface. The pulsing feature poweres the appliances displays and user interfaces on and stays on in standard setting, you can mess with the thresholds for the detection of loads to force the inverter to sleep again, but then they turn on and off all the time.

The second setting is the modified wave form thing, that causes 30% drop of the energy, but some gadgets really want a sine wave to operate properly and can get damaged otherwise. Also saving is marginal, around 0.5A less only (2.5...2.75A), so not worth the hussle.

I don't even know what all that means.
All I will say is our fridge has been running to ten years and on this particular victron 5kva inverter for 2.5 years without a problem.